I am working on a mx7001n with about 350k on it all the mntc is up to date. at about 250k it intermitently started shifting registration toward the lead edge. I did a registration adjustement to the high end of the spec. all was good till now. all color image shifts intermitently with no error codes . I did a 50-22 and no error but the problem is not fixed . I cleaned the sensors and could not find any phisical obstructions ..noises...codes.. .. any ideas? thanx